Treesearch

Species in the white-rot fungal genus Armillaria vary in parasitic aggressiveness as root and butt rot pathogens of trees. Armillaria genets (individuals) were mapped in the Throughfall Displacement Experiment (TDE) using mushrooms and rhizomorphs collected in 1994 and 1995. Initiated in July 1993, the TDE consists of three 80 x 80 m plots. The "ambient" plot receives natural precipitation; the "wet" plot also receives 33% of throughfall from the "dry" plot (which also had lower pre-treatment mean soil water content). Isolates from 36 rhizomorph and 48 mushroom collections of A. gallica...

Variations in nitrogen losses in streamflow on catchments in the Appalachians suggests that the level of nitrogen retention in hardwood forests varies widely. Stream losses of dissolved nitrate-N on several small experimental forested catchments range from about 0.2 to 8.5 kg ha-1 y-1. This wide range of losses is equivalent to less than 10% to nearly 100% of measured atmospheric nitrogen wet deposition in the region. Forest stand age and condition and levels of atmospheric wet N deposition do not correlate well with observed differences in catchment N losses. Variations in soil mineralizat...

The intent of this research was to empirically identify and estimate the relationship between perceived scenic beauty and biophysical resources of hardwood stands in southeast Missouri under various disturbance regimes. The scenic effects of different harvest methods, wind, and fire were systematically investigated using a psychophysical approach. Ratings of scenic beauty were collected from both residents and non-residents, and scaled using the Scenic Beauty Estimation (SBE) method. Quantitative, predictive models were generated to identify what biophysical features contributed to public...

Much progress has been made in developing and implementing individual silvicultural operations such as regeneration, thinning, and harvesting by various means. Similarly, foresters have made progress at managing flows of timber and other commodity values. Present concern that forests provide an even greater variety of commodity and non-commodity values can be accommodated by integrating management at the various levels--silvicultural operations, silvicultural regimes, landscape patterns, forest management, and policy. Using modern, systems management approaches, the integration can be done...

Precommercial, commercial, and final harvesting operations can impact wildlife habitat suitability by altering the vegetation composition on a given site. Harvesting operations remove trees and many times provide the necessary perturbation to trigger successional conditions different from those that existed prior to the harvest. Although these new successional changes can be beneficial to a wide array of wildlife species, they also can alter the site such that some wildlife species that were once abundant will no longer find the site suitable. In this paper, FOREX is used to demonstrate...

Woodland ecosystems in the Midwestern United States provide habitat for an impressive array of biodiversity, including endemic organisms. Sustainable conservation of high quality woodland landscapes must consider the genesis, process regimes, and ecological dynamics of these systems, both in contemporary and presettlement tine frames. An essential goal of conservation efforts must be to retain diverse aggregations of native biota. To this end, organismal considerations are requisite for implementing and monitoring woodland ecosystem management from a biodiversity standpoint. Examples of...

Today, there is an interest in using alternative silvicultural systems like selection and two-aged management, because the public finds these systems more acceptable than clearcutting. However, repeated entries into forest stands to remove timber increase the risk of residual stand damage. Harvest techniques are desirable that (1) reduce the risk of stand damage and (2) are economically efficient. Animal logging provides a feasible alternative to conventional rubber-tired skidder harvesting systems used in the Ozarks. Residual stand damage following selection harvests was examined for both...

The Central Hardwood Forest is an oak dominated deciduous forest that stretches from Massachusetts to Arkansas and occurs in hilly to mountainous terrain. It is the largest and most extensive temperate deciduous forest in the world. During the past 20 million years or so, angiosperms have been gradually replacing gymnosperms as the dominant plant form on earth, and deciduous hardwoods are particularly adapted to the fluctuating seasonal climate and moderate rainfall associated with the Central Hardwood Region. As the glacial ice sheets retreated about 12-14 thousand years ago, forests...

Naturally regenerated forests are the primary source of timber, fiber, and fuel throughout much of the world today. In the United States, however, public outcry over increasing forest fragmentation and habitat loss is reducing timber harvests in many areas. As our demand for forest products exceeds supplies, reliance on international timber resources will escalate, exacerbating global deforestation and timber shortages. Agroforestry-growing trees in intensively managed fiber or fuel farms-will lessen our demands on forest ecosystems in other parts of the world. Applications of plant...

The USDA Forest Service's Forest Inventory and Analysis (FIA) program and the Forest Health Monitoring (FHM) program maintain networks of sample locations providing coarse-scale information that characterize general indicators of forest health. Tree mortality is the primary FIA variable for analyzing forest health. Recent FIA inventories of New York, Pennsylvania, and West Virginia reveal that the current rate of mortality, expressed as percent of basal area of live trees, is 1.01. The Virginia Pine (Pinus virginiana) and Pitch Pine (Pinus rigida) forest types, growing along the ridges of...